Emil kolben



(No Model.)

f K E. KOLBEN.

CONDUCTOR POR ARMMURES.` y

Patented Feb. '14, 1893.

UNITED STATES PATENT OFFICE.

EMIL KOLBEN, OF SOIIENECTADY, ASSIGNOR TO THE EDISON GENERAL ELECTRICOOIWIPANY, OF NEW' YORK, N. Y.

CONDUCTOR FOR ARMATU RES.

SPECIFICATION forming part of Letters Patent No. 491,567, dated February14, 1898.

Application filed February 8, 1892. Serial No, 420,785. (No model.)

To all whom t may concern:

Be it known that I, EMIL KOLBEN, a subject of the Emperor ofAustria-Hungary, residing` at Schenectady, in the county of Schenectadyand State of New York, have invented a certain new and usefulImprovement in Conductors for Armatures, of which the following is aspecication.

The present invention relates to armatures for electro magneticmachines, and especially to the conductor forming the armature coil inmachines of large size, in which said conductor is necessarily large inorder thatitmay safely and economically conduct the heavy currents. Itis well known that when athick bar of copper is moved in a strongmagnetic iield, local or eddy currents are generated in the bar itself,and such currents are objectionable mainly because of the heat producedthereby.

The objects of the present invention are primarily to prevent theselocal or eddy currents in the large conductors, and to so form theconductor that it shall cover the armature core Without Waste of space,and the invention consists in the improved conductor and in the severalfeatures and combinations hereinafter described and specified in theclaims.

In the accompanying drawings illustrating the invention, Figure l is aperspective view of one section of the form of conductor which I employ;Fig. 2 is a sectional view through a portion of an armature, on a linecorresponding to x-x of Fig. l; Figs. 3 and a illustrate slightmodifications to be described.

In forming the armature coil I preferably employ a series of U, orsimilar shaped, metal bars l placed side by side on an insulated core 2,one end of each bar being connected to an end of the next adjacent barby a cross-piece 3, as more fully set forth in an application filed byme of even date herewith, Serial No. 420,784. The conductors may beinsulated from each other as set forth in said application. The severalconducting bars are, however, shown in this case insulated from eachother by simple layers of insulation 4;. In order to reduce orr preventthe formation of the eddy currents above referred to, I cut a sawkerf 5through the outerlimb of the U -shaped piece, as shown in Figs. 1 and 3,and this kerf is preferably filled with insulating material, although itis evident that it may be left as an air-space if desired. This saW-kerfis cut so that it occupies a radial plane in respect to the armaturecore and thus divides the bar so that it presents thin strips to thefield magnet poles. The ends of the U-shaped bars are milled to formtongues 6 and shoulders 7, the latter being at such distance in advanceof the end of the saw-kerf that the conductivity and strength of the barat this part will not be interfered with. The cross-piece 3 is providedWith corresponding milled or grooved ends S, adapted to fit the endsiirst mentioned, this also being more fully described in the applicationabove referred to. Evidently the tongue and groove arrangement may bereversed.

In Fig. 3 I have shown more than one sawkerf 5 through the upper limb ofthe U -shaped bar, these kerfs being filled with a suitable insulatingmaterial 5.

In Fig. et the conductor is shown as composed of two halves 9, l0,separated through a considerable portion of their length by theinsulation 1l, and secured together by suitable rivets or similardevices l2. This, it will be seen, separates the laininations of theupper limb of the bar but not those of the lower, where there is less orno need therefor.

In view of the fact that the outer circumference of the armature core isconsiderably longer than the inner circumference, it becomes importantto so form the conducting bars that they, together with the thininsulation between them, may be symmetrically arranged and may entirelycover the surface of the core. To accomplish this I form the U- shapedbars so that the sides 13 of the outer limbs, and the sides It of theinner limbs thereof are in substantially the same radial lines. This, itwill be seen, gives to the outer limbs a greater Width than to theinnerlimbs, and in orderthat the area of the cross-section and theconductivity of the two limbs in each conductor may be maintained equal,the inner limb is made correspondingly thicker. By this construction thewidth of the outer limbs bears the same relation to the outercircumference of the core that the width of the inner limbs does to theinner circumference IOC) of the core, thus causing the conductors, whenthe several bars are placed side by side, to e11- tirely cover thesurface of the core, without the use of large quantities of insulationto lill up spaces,or without leavinglarge open spaces between theconductors on the outer periphery of the armature. Making the bar on theoutside of the armature core comparatively thin between its outer andinner faces, and comparatively thick or Wide in the opposite direction,is advantageous also when the armature is run in fields of the outsidetype, inasmuch as it reduces themagnetic resistance due to the gapbetween the field and the iron core.

It will be apparent that the benet derived from the lamination producedby the kerf or kerfs in the upper limb of the conductor is not dependenton having said conductor of the particular contour shown, and the termU-shaped is employed to define, not only that exact shape, but othersimilar shapes adapted to be used in the same general manner.

It will further be evident that a part of the advantages resulting fromforming the inner and outer limbs of the conductor with faces in thesame radial lines, might be attained, though less perfectly, by lnakingthe outer and inner limbs wide and thin respectively,

but making the faces 13, 14 parallel instead of making them in radialplanes.

What I claim is,

l. A U-shaped bar conductor adapted to form part of an armature coil andhaving one limb wider than the other and having a radial saW-kerfdividing the Wider limb for a part of its length only, substantially asdescribed.

2. A U-shaped conductor adapted to form a part of an armature coil, oneleg of said conductor bein g laminated, an d the other leg and thesection connecting the two legs being solid, substantially as described.

3. A U -shaped conductor having milled ends and adapted to form a partof an armature coil, one leg of said conductor being laminated, theother leg and the section connecting the two legs being solid, and aconductor milled to fit one of said ends and adapted to connect it to asimilar adjacent conductor, substantially as described.

This specification signed and witnessed this 22d day of January, 1892.

EMIL KOLBEN.

XVitnesses:

FREDERICK BArI-Iunsr, GEORGE H, RUPLEY.

